terminal

Documentation

Overview

Package terminal provides methods for working with user input

Index

• Variables
• func AddHistory(data string)
• func Error(message any, args ...any)
• func Info(message any, args ...any)
• func PrintActionMessage(message string)
• func PrintActionStatus(status int)
• func PrintErrorMessage(message string, args ...any)
• func PrintWarnMessage(message string, args ...any)
• func Read(title string, nonEmpty bool) (string, error)
• func ReadAnswer(title string, defaultAnswers ...string) (bool, error)
• func ReadPassword(title string, nonEmpty bool) (string, error)
• func ReadPasswordSecure(title string, nonEmpty bool) (*secstr.String, error)
• func ReadUI(title string, nonEmpty bool) (string, error)
• func SetCompletionHandler(h func(input string) []string)
• func SetHintHandler(h func(input string) string)
• func Warn(message any, args ...any)

Examples

• Error
• Info
• PrintActionMessage
• PrintActionStatus
• Read
• ReadAnswer
• ReadPassword
• ReadPasswordSecure
• Warn

Variables

var (
	// MaskSymbolColorTag is fmtc color tag used for MaskSymbol output
	MaskSymbolColorTag = ""

	// TitleColorTag is fmtc color tag used for input titles
	TitleColorTag = "{s}"

	// ErrorColorTag is fmtc color tag used for error messages
	ErrorColorTag = "{r}"

	// WarnColorTag is fmtc color tag used for warning messages
	WarnColorTag = "{y}"

	// InfoColorTag is fmtc color tag used for info messages
	InfoColorTag = "{c-}"
)

var (
	// ErrorPrefix is prefix for error messages
	ErrorPrefix = ""

	// WarnPrefix is prefix for warning messages
	WarnPrefix = ""

	// InfoPrefix is prefix for info messages
	InfoPrefix = ""
)

var AlwaysYes = false

AlwaysYes is a flag, if set ReadAnswer will always return true (useful for working with option for forced actions)

var ErrKillSignal = linenoise.ErrKillSignal

ErrKillSignal is error type when user cancel input

var HideLength = false

HideLength is flag for hiding password length

var HidePassword = false

HidePassword is flag for hiding password while typing Because of using the low-level linenoise method for this feature, we can not use a custom masking symbol, so it always will be an asterisk (*).

var MaskSymbol = "*"

MaskSymbol is symbol used for masking passwords

var Prompt = "> "

Prompt is prompt string

Functions

func AddHistory

func AddHistory(data string)

AddHistory adds line to input history

func Error

func Error(message any, args ...any)

Error prints error message

Example

// Add custom error message prefix
ErrorPrefix = "▲ "

// Print red text to stderr
Error("Error while sending data to %s", "https://example.com")

// Print message from error struct
err := errors.New("My error")
Error(err)

func Info

func Info(message any, args ...any)

Info prints info message

Example

// Add custom info message prefix
InfoPrefix = "❕ "

// Print cyan text to stdout
Warn("User %q will be created automatically", "bob")

func PrintActionMessage

func PrintActionMessage(message string)

PrintActionMessage prints message about action currently in progress

Example

statusOk := true

PrintActionMessage("Starting service my-service")

switch statusOk {
case true:
	PrintActionStatus(0) // Print OK
case false:
	PrintActionStatus(1) // Print ERROR
}

func PrintActionStatus

func PrintActionStatus(status int)

PrintActionStatus prints message with action execution status

Example

statusOk := true

PrintActionMessage("Starting service my-service")

switch statusOk {
case true:
	PrintActionStatus(0) // Print OK
case false:
	PrintActionStatus(1) // Print ERROR
}

func PrintErrorMessage

func PrintErrorMessage(message string, args ...any)

PrintErrorMessage prints error message

Deprecated: Use method Error instead

func PrintWarnMessage

func PrintWarnMessage(message string, args ...any)

PrintWarnMessage prints warning message

Deprecated: Use method Warn instead

func Read

func Read(title string, nonEmpty bool) (string, error)

Read reads user's input

Example

// User must enter name
input, err := ReadUI("Please enter user name", true)

if err != nil {
	fmt.Printf("Error: %v", err)
}

fmt.Printf("User name: %s\v", input)

// You can read user input without providing any title
fmt.Println("Please enter user name")
input, err = ReadUI("", true)

if err != nil {
	fmt.Printf("Error: %v", err)
}

fmt.Printf("User name: %s\v", input)

func ReadAnswer

func ReadAnswer(title string, defaultAnswers ...string) (bool, error)

ReadAnswer reads user's answer for yes/no question

Example

// If the user doesn't enter any value, we will use the default
// value (Y in this case)
ok, err := ReadAnswer("Remove this file?", "Y")

if !ok || err != nil {
	return
}

if ok {
	fmt.Println("File removed")
}

func ReadPassword

func ReadPassword(title string, nonEmpty bool) (string, error)

ReadPassword reads password or some private input which will be hidden after pressing Enter

Example

Prompt = "› "
MaskSymbol = "•"
MaskSymbolColorTag = "{s}"

// User must enter the password
password, err := ReadPassword("Please enter password", true)

if err != nil {
	fmt.Printf("Error: %v", err)
}

fmt.Printf("User password: %s\v", password)

func ReadPasswordSecure

func ReadPasswordSecure(title string, nonEmpty bool) (*secstr.String, error)

ReadPasswordSecure reads password or some private input which will be hidden after pressing Enter

Example

Prompt = "› "
MaskSymbol = "•"
MaskSymbolColorTag = "{s}"

// User must enter the password
password, err := ReadPasswordSecure("Please enter password", true)

if err != nil {
	fmt.Printf("Error: %v", err)
}

fmt.Printf("User password: %s\v", string(password.Data))

password.Destroy()

func ReadUI

func ReadUI(title string, nonEmpty bool) (string, error)

ReadUI reads user's input

Deprecated: Use method Read instead

func SetCompletionHandler

func SetCompletionHandler(h func(input string) []string)

SetCompletionHandler adds function for autocompletion

func SetHintHandler

func SetHintHandler(h func(input string) string)

SetHintHandler adds function for input hints

func Warn

func Warn(message any, args ...any)

Warn prints warning message

Example

// Add custom warning message prefix
WarnPrefix = "△ "

// Print yellow text to stderr
Warn("Warning file %s is not found", "/home/john/test.txt")

// Print message from error struct
err := errors.New("My warning")
Warn(err)